HUDSON, WIS. - Aaron Schaffhausen sat shackled and almost motionless in court Tuesday as attorneys contentiously debated whether mental health professionals at the St. Croix County jail should even be allowed to approach him in his cell, where he sits on suicide watch, charged with murdering his children.

Schaffhausen, accused of killing his three young daughters in their River Falls home in July, has been housed in solitary confinement, attorneys said in an afternoon arraignment hearing. When asked how he pleaded to the homicide and arson charges lodged against him, Schaffhausen's attorney, John Kucinski, answered for his client, saying they opted to "stand mute." The court, by law, then entered a plea of not guilty.

Schaffhausen spoke little and softly during the hearing, only answering the judge's questions "yes" that he understood the charges and their penalties.

Schaffhausen was charged July 12 with three counts of first-degree intentional homicide for the murders of his daughters, 11-year-old Amara, 8-year-old Sophie and 5-year-old Cecilia. Authorities found all three of the girls tucked into their beds, blankets drawn to their necks. The older girls' throats had been slit. Cecilia was strangled and her throat was cut in two places, authorities testified.

Authorities also found a gas fireplace turned on and gasoline poured in the basement. Prosecutors last week added a charge of arson.

Schaffhausen, a divorced carpenter living in Minot, N.D., shared legal custody of the girls, who lived with their mother in River Falls. He had been fired when, according to a criminal complaint, he called and texted his ex-wife around noon on July 10, saying he was nearby and asking to spend time with the children at the family home. She agreed but told him he had to leave the house by 3:30 p.m., before she got home, the complaint says. A baby sitter said the girls were excited to see him and led him upstairs to show him their things, the document says. The baby sitter left and at 3:30, Jessica Schaffhausen told police, she got a call from her ex-husband telling her he had killed the children.

Video (59:31): Prosecution talks about Schaffhausen arraignment

Aaron Schaffhausen faces the possibility of life in prison on each intentional homicide charge.

Assessing mental status

Much of the Tuesday hearing focused on whether the St. Croix County Sheriff's Office could send a mental health worker to check in on Schaffhausen and whether Schaffhausen, 35, had to respond.

"We don't want anybody invading his 5th- or 6th-amendment right to remain silent," Kucinski argued to the judge. He later added: "This is not a simple question, 'Sir, are you thinking of committing suicide? Sir, do you have a plan to commit suicide?' They want to go in there and ask things like, 'Are you feeling hopeless? You feeling helpless? Have you experienced any loss? Are you depressed? You have any strange feelings?'"

An attorney appearing on behalf of the Sheriff's Office, Don Gillen, argued the sheriff has a duty to check on Schaffhausen's mental health.

Schaffhausen "has an absolute right to remain silent if he wants to, but the sheriff ... has a duty to provide health care to the defendant, and that's what we're doing," Gillen said.

The mental health worker isn't seeking information on the case, but simply assessing the defendant's current mental status, Gillen argued.

Kucinski argued that the mental health worker, who contracts with the Sheriff's Office, acts as an agent of the sheriff.

Judge Howard Cameron said the Wisconsin Constitution is very clear about the sheriff's responsibilities and ruled that it would be OK for the mental health worker to state his name, his purpose and ask Schaffhausen whether he'd like to talk about his mental health.

"You're saying my client has to answer him?" Kucinski asked.

"All he has to say is 'I don't wanna talk.' Period," the judge replied.

Prosecutor Gary Freyberg suggested that if the mental health worker asks questions and gets no response, that could satisfy the worker's attempts.

"I think not responding by Mr. Schaffhausen would be enough, at least from my point of view," he said, and the Sheriff's Office agreed.

In the courthouse hall after the hearing, Kucinski said he will consider appealing the judge's ruling on that point.

"The state can talk to your client even though he has a 5th-amendment right not to. They just try to get information from him," Kucinski told throngs of cameras. "Well, how long will he [Schaffhausen] have to stand there before that's considered a no?"

Kucinski said he didn't officially enter a plea because he didn't have all the discovery in the case yet.

Jeff Wheeler, Star Tribune

Aaron Schaffhausen was arraigned in St. Croix County Circuit Court in Hudson, Wis., Tuesday afternoon. He is accused of killing his three daughters.

"Until you find out what the facts are, you can't very well enter a plea," he said.

During the hearing, the judge agreed to review a set of documents that Freyberg had called "sensitive" including autopsy photographs. They will discuss the documents at a hearing scheduled for Sept. 20.

The court gallery was about half full, mostly with media. Jessica Schaffhausen's family did not attend, said her uncle Flint Watt.

"It is very difficult," on the family, he said, adding that Jessica Schaffhausen "has good days, and she has bad days."

They were grateful to see the support at a dance recital benefit held over the weekend, he said.